Real-time characterisation of food and beverages with electronic nose

by EJ Staples, Electronic Sensor Technology

 

Published in:

Electricity+Control, September 2014 – pages 34 - 39

Enquiries: Email kzeiger@estcal.com

 

Download the full article on Real-time characterisation of food and beverages with electronic nose in PDf format

 

An array of sensors simulating the human olfactory response has become known as an electronic Nose [1]. Electronic noses provide recognisable visual images in N-dimensional space (where N equals the number of sensors) of specific vapour mixtures (fragrances). An electronic nose, based upon fast chromatography, is able to simulate a sensor array containing hundreds of orthogonal (non-overlapping) sensors. Chemical analysis of any odour is accomplished in 10 seconds by a very fast separation of chemicals in sampled vapours. For a chromatography system, chemical sensor space is defined mathematically by assigning unique retention time slots to each sensor. Part per billion (ppb) sensitivity has been achieved with volatile compounds and part per trillion (ppt) sensitivity for semi-volatile compounds.

A new type of electronic nose using fast chromatography can now provide a recognisable visual image of specific vapour mixtures (fragrances) containing hundreds of different chemical species. The electronic nose is fast (10 seconds), operates over a wide range of vapour concentrations, has picogram sensitivity, and is simple to use and calibrate. It is used for quality control of virtually any food or beverage.

Unlike an array of physical sensors, a fast gas chromatography system with an integrating detector can transform the human olfactory response into a true visual response. Viewed as a virtual sensor array, the GC/SAW electronic nose can produce an olfaction response consistent with serially polling an array of hundreds of orthogonal chemical sensors. The GC/SAW simultaneously is able to quantify the concentration of the individual chemical compounds. Quality control of virtually any food or beverage can be achieved with speed, precision and accuracy. Validation by the US EPA and other governing agencies is an assurance that quality control of the measurement itself can be verified.

Please see pdf for references.

 

Take note

  • Early electronic noses rejected chromatography techniques because they were slow.
  • The latest electronic nose uses fast chromatography.
  • The electronic nose makes quality control of almost any food or beverage possible with speed, precision and accuracy.